System for determining and monitoring at least one process variable of a medium

Abstract

A system for determining a process variable of a medium arranged in a container is disclosed, including an optical fiber Bragg sensor with an optical waveguide with a fiber Bragg grating, a signal generating unit designed to generate an optical input signal and couple it into the waveguide, a receiving unit designed to receive an optical output signal from the waveguide and converts it into an electrical output signal, and an evaluating unit which determines the process variable using the electrical output signal, wherein a subsection of the optical waveguide is arranged inside or in a wall of the container, the subsection designed such that the fiber Bragg grating is affected by the process variable to be determined of the medium.

Claimed is: 
     
         1 . A system for determining at least one process variable of a medium arranged in a container, comprising:
 an optical fiber Bragg sensor with an optical waveguide including at least one fiber Bragg grating, which is configured to be affected by the at least one process variable of the medium to be determined;   a signal generating unit embodied to generate an optical input signal and to couple the input signal into the optical waveguide;   a receiving unit embodied to receive an optical output signal from the optical waveguide and to convert the optical output signal into an electrical output signal; and   an evaluating unit configured to determine the at least one process variable based upon the electrical output signal,   wherein a subsection of the optical waveguide is disposed within the container or in or adjacent a wall of the container, and wherein the subsection of the optical waveguide includes the at least one fiber Bragg grating arranged to interact with the medium.   
     
     
         2 . The system of  claim 1 , wherein the optical waveguide includes a core and a cladding surrounding the core at least partially, wherein the core is composed of a material having a higher refraction index than a material of the cladding. 
     
     
         3 . The system of  claim 1 , wherein the optical waveguide includes of a fiber having a higher refraction index than the medium interacting with the at least one fiber Bragg grating. 
     
     
         4 . The system of  claim 1 , wherein the optical waveguide includes Bragg grating groups at defined intervals, wherein a fiber Bragg grating group is configured such that at least two different process variables can be determined selectively. 
     
     
         5 . The system of  claim 1 , wherein the optical waveguide is embodied such that at least one fiber Bragg grating or at least one fiber Bragg grating of a fiber Bragg grating group interacts with the medium via an evanescent field to enable determining the at least one process variable of the medium. 
     
     
         6 . The system of  claim 1 , wherein the optical waveguide includes a surface layer in a subregion of the optical waveguide, wherein the surface layer is embodied to increase a sensitivity of the at least one fiber Bragg grating to the the at least one process variable of the medium to be determined. 
     
     
         7 . The system of  claim 1 , wherein a wall of the container includes a duct configured such that at least one of two end regions of the optical waveguide extends out of the container. 
     
     
         8 . The system of  claim 1 , wherein a wall of the container includes a coupling component configured such that at least one of two end regions of the at least one optical waveguide is connected or connectable to the coupling component. 
     
     
         9 . The system of  claim 1 , wherein the wall of the container includes at least one coupling region embodied as a window transparent to the optical input signal and optical output signal, and wherein at least one of two end regions of the at least one optical waveguide is connected or connectable to a lens system. 
     
     
         10 . The system of  claim 1 , wherein the optical waveguide is arranged at least partially on a substrate or is integrated at least partially into a substrate. 
     
     
         11 . The system of  claim 10 , wherein the substrate is at least a portion of a wall of the container or is a coating on a wall of the container. 
     
     
         12 . The system of  claim 10 , wherein the receiving unit is disposed on the substrate or integrated into the substrate. 
     
     
         13 . The system of  claim 1 , wherein the receiving unit is a photoelectric converter. 
     
     
         14 . The system of  claim 1 , wherein the signal generating unit, the receiving unit and/or the evaluating unit are diposed outside the container. 
     
     
         15 . The system of  claim 1 , further comprising a control system configured to communicate with the evaluating unit, the communication being wired or wireless. 
     
     
         16 . The system of  claim 1 , wherein the container is a single-use or disposable container. 
     
     
         17 . The system of  claim 1 , wherein the medium is a fluid medium, including a gas, gas mixture, liquid, granulate and/or powder. 
     
     
         18 . The system of  claim 1 , wherein the optical fiber Bragg sensor is embodied to determine at least one of the following physical or chemical process variables: temperature, pressure, fill-level, flow rate, mechanical stress, pH value, turbidity, concentration of a substance, an atomic or molecular gas, or a portion of at least one gaseous, liquid, or solid component. 
     
     
         19 . The system of  claim 1 , wherein the optical fiber Bragg sensor is embodied to determine the color of the medium. 
     
     
         20 . The system of  claim 1 , wherein the optical fiber Bragg sensor is embodied to determine at least one metabolite or the concentration of a metabolite, wherein the metabolite is an intermediate product in a biochemical metabolic process. 
     
     
         21 . The system of  claim 1 , wherein the optical input signal is coupled into the optical waveguide at a power that is less than the maximum power permissible for an explosion-hazard area. 
     
     
         22 . The system of  claim 1 , wherein the system is powered at a power that is less than the maximum power permissible for the explosion-hazard area.